Based on the output above, which of following is the MOST probable cause of the issue?

A systems administrator is troubleshooting connectivity issues and trying to find out why a Linux server is not able to reach other servers on the same subnet it is connected to.

When listing link parameters, the following is presented:

Based on the output above, which of following is the MOST probable cause of the issue?
A . The address ac:00:11:22:33:cd is not a valid Ethernet address.
B . The Ethernet broadcast address should be ac:00:11:22:33:ff instead.
C . The network interface eth0 is using an old kernel module.
D . The network interface cable is not connected to a switch.

View Answer

Answer: D

Explanation:

The most probable cause of the connectivity issue is that the network interface cable is not connected to a switch. This can be inferred from the output of the ip link list dev eth0 command, which shows that the network interface eth0 has the NO-CARRIER flag set. This flag indicates that there is no physical link detected on the interface, meaning that the cable is either unplugged or faulty. The other options are not valid causes of the issue. The address ac:00:11:22:33:cd is a valid Ethernet address, as it follows the format of six hexadecimal octets separated by colons. The Ethernet broadcast address should be ff:ff:ff:ff:ff:ff, which is the default value for all interfaces. The network interface eth0 is not using an old kernel module, as it shows the UP flag, which indicates that the interface is enabled and ready to transmit data.

Reference: CompTIA Linux+ (XK0-005) Certification Study Guide, Chapter 14: Managing Networking